Cytotoxicity assessment of four pharmaceutical compounds on the zebra mussel (Dreissena polymorpha) haemocytes, gill and digestive gland primary cell cultures

Pharmaceutical compounds are considered the new environmental pollutants but at present few studies have evaluated their ecotoxicity on aquatic invertebrates. This study was aimed to investigate the in vitro cytotoxicity of four common drugs, namely atenolol (ATL), carbamazepine (CBZ), diclofenac (DCF) and gemfibrozil (GEM), on three different cell typologies from the zebra mussel (Dreissena polymorpha): haemocytes, gill and digestive gland cells. Results obtained by the Trypan blue exclusion test revealed that exposure to increasing concentrations (0.001; 0.01; 0.1; 1 and 10 mg L⁻¹) of CBZ, DCF and GEM were able to significantly decrease the viability of each cell type, while the MTT (3(4,5-dimethyl-2thiazholyl)-2,5-diphenyl-2H-tetrazolium bromide) reduction assay highlighted only a slight reduction of mitochondrial activity of gill and digestive gland cells. Overall, DCF was the most cytotoxic drug for zebra mussel cells, followed by GEM, CBZ, while ATL has not a noteworthy toxic potential. Our preliminary results lay the groundwork for further in vitro evaluations, which will allow a better definition of the potential toxicity of these drugs.     

Sperm exchange in a simultaneous hermaphrodite

Many simultaneously hermaphroditic animals cross-inseminate when copulating, even though unilateral sperm exchange is functionally possible. The question is why reciprocity is the rule. This study addresses sperm exchange in a hermaphroditic planarian flatworm, Dugesia polychroa, in which self-fertilisation does not occur. We investigated the availability of self sperm for inseminating a partner, how self sperm affects the likelihood of sperm donation, and whether sperm donation depends on reciprocation by the partner. The amount of self sperm depended on body size, duration of isolation and experimental date, and animals that had more self sperm were more likely to mate. Depletion of allosperm (sperm received from partners) played only an indirect role, suggesting that animals copulate more to donate sperm rather than to replenish allosperm reserves. Among 60 copulating pairs, reciprocal insemination was more common (63.3%) than unilateral transfer (18.3%). A surprising 18.3% did not exchange sperm in either direction. Individuals were more likely to behave like their partners, resulting in more symmetrical matings (either reciprocity or no sperm exchange) than asymmetrical matings (unilateral sperm donation). The amount of self sperm donated during a copulation depended mainly on the amount available before the copulation and not on the amount received from the partner. The results suggest that conditional sperm exchange, or sperm trading, takes place in D. polychroa. Received: 31 May 1997 / Accepted after revision: 1 December 1997     

Towards a spatial information infrastructure for flood management in The Netherlands

The immense value of a geographic information system for flood control has been experienced by the decision-markers of the Dutch province of Gelderland during the flood of the Rivers Meuse (Maas) and Waal in January 1995. Super-imposing different ‘data layers’, GIS-experts could detect the weak parts in the dikes and generate and evacuation plan. Shortcomings within the organization were experienced as well: important data could not be retrieved, and the coordination of efforts by the different governmental departments and institutions was not optimal. To overcome these shortcomings and to optimize the modelling process, a spatial decision support system (SDSS) is being proposed, aggregating several models, heuristic and procedural, into integrated software tools. As becomes clear from two cases of flood control described, ‘emergency managers’ should be able to communicate about spatial data available and have access to selected spatial data. In order to improve communication between data sources, data processing and the use of relevant spatial data in GISs, a new ‘Spatial Information Infrastructure’ (SII) needs to be developed. This requires both technical and organizational solutions and standards. Proper documentation of the data will allow the GIS-experts to more quickly find, store, update and reuse the data. A range of ‘metadata’ services exist documenting data sets, typically limited by thematic or national boundaries. There are no standards in common practice for structuring and classifying spatial information. The user of spatial information cannot easily browse across Web-sites and compare products from different suppliers. Even, if the search has been successful, the user all too often has to face a complex process of negotiation, and highly technical data integration issues. A consortium of European GIS-experts has addressed these problems and launched the ‘European Spatial Metadata Infrastructure’ (ESMI) project with the objective to link existing and future metadata systems using Internet.     

Biomonitoring von Immissionswirkungen durch verkehrsbedingte Schwermetalle in einem Heideökosystem

In a part of the Lüneburger Heide situated along a motorway, the deposition of several heavy metals caused by traffic were analysed again after eleven years. As a consequence of new techniques in car production, as well as of a change in car emissions, samples of soil, plants and insects collected in 1996 showed clearly higher concentrations of lead and cadmium than those taken in 1985. For the first time, antimony and platinum were investigated. Antimony was detected in all compartments of the heathland ecosystem, while platinum was only measured in mosses, lichens and litter. Mosses were the best indicators to evaluate the impact of the ecosystem by particular emissions from traffic.     

Gas-particle concentration and distribution of n-alkanes and polycyclic aromatic hydrocarbons in the atmosphere of Prato (Italy)

Air samples were collected in an urban and industrialised area of Prato (Italy) during 2002, as part of a study to identify and measure aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs). Total concentrations of aliphatic hydrocarbons ranged between 170 and 282ngm(-3) in the gas phase and from 48.9 to 276ngm(-3) in the particulate phase. The average total PAH concentrations (gas+particulate) were 59.4+/-26.5ngm(-3), and both gas and particulate phase PAH concentrations decreased with increasing temperature. Source identification using diagnostic ratios and principal component analysis identified automobile traffic, in particular, the strong influence of diesel fuel burning, as the major PAH source. Gas-particle partition coefficients (K(p)'s) of n-alkane and PAHs were well correlated with the sub-cooled liquid vapour pressure (P(L)(0)) and indicate stronger sorption of PAHs to aerosol particles compared with n-alkanes.     

Occurrence of pharmaceutically active and non-steroidal estrogenic compounds in three different wastewater recycling schemes in Australia

The discovery that natural and synthetic chemicals, in the form of excreted hormones and pharmaceuticals, as well as a vast array of compounds with domestic and industrial applications, can enter the environment via wastewater treatment plants and cause a wide variety of environmental and health problems even at very low concentrations, suggests the need for improvement of water recycling. Three Australian wastewater recycling schemes, two of which employ reverse osmosis (RO) technology, the other applying ozonation and biological activated carbon filtration, have been studied for their ability to remove trace organic contaminants including 11 pharmaceutically active compounds and two non-steroidal estrogenic compounds. Contaminant concentrations were determined using a sensitive analytical method comprising solid phase extraction, derivatization and GC with MS using selected ion monitoring. In raw wastewater, concentrations of analgesics and non-steroidal anti-inflammatory medications were comparable to those found in wastewaters around the world. Remarkably, removal efficiencies for the three schemes were superior to literature values and RO was responsible for the greatest proportion of contaminant removal. The ability of RO membranes to concentrate many of the compounds was demonstrated and highlights the need for continued research into monitoring wastewater treatment, concentrate disposal, improved water recycling schemes and ultimately, safer water and a cleaner environment.     

Behavior of fenhexamid in soil and water

A study was conducted to investigate fenhexamid (FEX) behavior in soil and in water. FEX proved to be rather stable at acid pH but showed slight degradation at neutral and alkaline pH. After 101 days of FEX spiking of a soil sample, 94% at pH 4, 12% at pH 7 and 23% at pH 9 of the active ingredient was still present. In natural water the rate of FEX disappearance appeared to be slow which may be due to abiotic rather than biotic processes. The soil degradation tests showed low persistence of the active ingredient if a good microflora activity is guaranteed (DT(50) about 1 day). Moreover, in absence of microorganisms, FEX proved to be stable. Humidities of 25 and 50% of Water Holding Capacity (WHC) influenced in equal measure the rate of degradation. From the same soil, a bacterium was isolated and identified as Bacillus megaterium, which was able to metabolize FEX with the hydroxylation of the cyclohexane ring. Moreover, FEX showed an elevated affinity for humic acid (73%), smectite (31%), and ferrihydrite(20%) and low affinity for vermiculite (11%) and kaolinite (7%).     

Indoor/Outdoor relationships, trends, and carbonaceous content of fine particulate matter in retirement homes of the Los Angeles Basin

Hourly indoor and outdoor fine particulate matter (PM2.5), organic and elemental carbon (OC and EC, respectively), particle number (PN), ozone (O3), carbon monoxide (CO), and nitrogen oxide (NOx) concentrations were measured at two different retirement communities in the Los Angeles, CA, area as part of the Cardiovascular Health and Air Pollution Study. Site A (group 1 [G1]) was operated from July 6 to August 20, 2005 (phase 1 [P1]) and from October 19 to December 10, 2005 (P2), whereas site B (group 2 [G2]) was operated from August 24 to October 15, 2005 (P1), and from January 4 to February 18, 2006 (P2). Overall, the magnitude of indoor and outdoor measurements was similar, probably because of the major influence of outdoor sources on indoor particle and gas levels. However, G2 showed a substantial increase in indoor OC, PN, and PM2.5 between 6:00 and 9:00 a.m., probably from cooking. The contributions of primary and secondary OC (SOA) to measured outdoor OC were estimated from collected OC and EC concentrations using EC as a tracer of primary combustion-generated OC (i.e., "EC tracer method"). The study average outdoor SOA accounted for 40% of outdoor particulate OC (40-45% in the summer and 32-40% in the winter). Air exchange rates (hr(-1)) and infiltration factors (Finf; dimensionless) at each site were also determined. Estimated Finf and measured particle concentrations were then used in a single compartment mass balance model to assess the contributions of indoor and/or outdoor sources to measured indoor OC, EC, PM2.5, and PN. The average percentage contributions of indoor SOA of outdoor origin to measured indoor OC were approximately 35% (during G1P1 and G1P2) and approximately 45% (for G2P1 and G2P2). On average, 36% (G2P1) to 44% (G1P1) of measured indoor OC was composed of outdoor-generated primary OC.     

Water quality indices across Europe--a comparison of the good ecological status of five river basins

The European Water Framework Directive (WFD) requires the definition of near-natural reference conditions to determine the extent of water bodies' deviation from "good ecological status" caused by stress gradients. However, the classification of ecological quality depends on the assessment method applied and the stressor concerned. While assessment methods that are generally applicable would be favourable, many European countries employ the locally developed water quality metrics that assess the impact of organic pollution (including eutrophication) and the associated decrease in dissolved oxygen. These indices do not specifically address stress from organic toxicants, such as pesticides. The aim of this study was to examine the performance of presently used assessment methods to identify reference conditions of non-contaminated streams in five selected European river basins, covering the geographical region from Spain to Finland, as a crucial prerequisite to indicate toxic gradients. The analysis comprised the Belgium biotic index (BBI), the biological monitoring working party (BMWP) scoring system and the revised German saprobic index. For comparison, we included an adaptation of the recently developed SPEAR index. In two previous field studies, this metric highly correlated with measured pesticide gradients. In this study, SPEAR was the only indicator that was generally applicable to all monitoring data and capable of determining "high ecological status" of reference conditions in all basins. Thus, based upon previous and own results, the authors suggest the species at risk (SPEAR) index to be potentially useful as a European-wide index to address deviations from "good ecological status" due to organic toxicants and recommend it for consideration in integrated water-resource evaluations under the WFD.     

Evaluating the effect of rainfall variability on vegetation establishment in a semidesert grassland

Of the operations required for reclamation in arid and semi-arid regions, establishing vegetation entails the most uncertainty due to reliance on unpredictable rainfall for seed germination and seedling establishment. The frequency of successful vegetation establishment was estimated based on a land surface model driven by hourly atmospheric forcing data, 7 years of eddy-flux data, and 31 years of rainfall data at two adjacent sites in southern Arizona, USA. Two scenarios differing in the required imbibition time for successful germination were evaluated—2 or 3 days availability of sufficient surface moisture. Establishment success was assumed to occur if plants could germinate and if the drying front in the soil did not overtake the growth of seminal roots. Based on our results, vegetation establishment could be expected to fail in 32 % of years. In the worst 10-year span, six of ten plantings would have failed. In the best 10-year span, only one of ten was projected to fail. Across all assessments, at most 3 years in a row failed and 6 years in a row were successful. Funding for reclamation seeding must be available to allow reseeding the following year if sufficient amount and timing of rainfall does not occur.